1. Field of the Invention
The present invention relates to an optical assembly and, more particularly, to a leadframe-based optical assembly.
2. Description of the Prior Art
When packaged for use as indicator devices, visible light-emitting diodes (LEDs), such as GaP or GaAsP LEDs, are often attached to a leadframe to provide the required electrical connections, and encapsulated in a plastic or other transparent material to provide mechanical protection. See, for example, U.S. Pat. No. 4,129,682 issued to W. P. Stewart et al. on Dec. 12, 1978. Since a visible LED is used primarily as an indicator bulb (in key telephone sets, for example) the direct attachment thereto of an optical signal path, such as an optical fiber or waveguide, is not required.
Alternatively, for optical communication applications, a semiconductor optical device (i.e., LED or photodiode) must be both electrically connected to an associated transmitter or receiver circuit and optically coupled to an associated optical data signal path. The packaged optical assembly generally comprises a separate optical submount for holding the optical device and some sort of arrangement for inserting an optical fiber through the package and aligning the fiber to the optical device. In general, the electrical leads to the optical device are physically attached to the optical submount and exit through the package to associated external circuitry. See, for example, U.S. Pat. No. 4,296,998 issued to W. H. Dufft on Oct. 27, 1981.
The optical assembly, as described above, is often a relatively expensive item, since each assembly must be individually packaged. In most cases, the packing requires a number of individual manual operations including, but not limited to, mounting the optical device, attaching the electrical leads to the optical device, inserting the optical fiber, aligning the optical fiber to the device and attaching the aligned fiber to the package. The use of such a large number of manual operations necessitates that the package dimensions be sufficiently large to allow for manipulation of the various piece parts by the assembler.
In light of the above, there exists a need for reducing the cost, size and complexity of such packaged optical assemblies.